LeetCode/111. MinimumDepthOfBinaryTree

Link

• https://leetcode.com/problems/minimum-depth-of-binary-tree/

Summary

Finding minimum depth of binary tree.

Solutions

Best solution gives me a better idea. Don’t need to use targetNode pointer, because when one of those are null I just have to add them.(Cuz it will return 0);

My Solution

public int MinDepth(TreeNode root)
{
    if (root == null) return 0;

    if (root.left != null && root.right != null)
    {
        return Math.Min(MinDepth(root.left), MinDepth(root.right)) + 1;
    }
    else
    {
        var targetNode = root.left == null ? root.right : root.left;
        return MinDepth(targetNode) + 1;
    }
}

Best Solution

public int MinDepthBestSolution(TreeNode root)
{
    if (root == null) return 0;
    var left = MinDepth(root.left);
    var right = MinDepth(root.right);
    return root.left != null && root.right != null ? Math.Min(left, right) + 1 : left + right + 1;
}